WHO raises concerns over US vaccine trial in Guinea-Bissau.

The WHO voiced scientific and ethical concerns about a US-funded hepatitis B vaccine trial in Guinea-Bissau and said the country has paused the study pending further technical review.

WHO has voiced serious scientific and ethical concerns about a planned US-funded hepatitis B vaccine trial in Guinea-Bissau. The agency emphasised that the hepatitis B birth dose is an effective and essential public health intervention with a long safety record. WHO said the proposed study's design raised questions about scientific justification and ethical safeguards. Guinea-Bissau has suspended the trial pending further technical reviews. Key points: - WHO said the trial raised concerns about scientific justification, ethical safeguards, and alignment with established principles for research involving human participants. - WHO stated the hepatitis B birth dose prevents mother-to-child transmission and has a decades-long safety record used by more than 115 countries. - The agency said placebo or no-treatment vaccine trials are acceptable only when no proven intervention exists, and said neither condition appears to be met for this study. - Guinea-Bissau has suspended the US-funded study and the WHO said it is ready to support the country as technical reviews proceed. Summary: The WHO's statement highlights scientific and ethical objections to the planned trial and reaffirms the established role of the hepatitis B birth dose. Guinea-Bissau has suspended the study and the WHO offered support while technical reviews are carried out. Undetermined at this time.